By mid-summer the aquatic hatches thin out, but the trout still have to eat, and that is when land insects, terrestrials, become a huge part of the menu. Grasshoppers, ants and beetles blunder into the water off the banks on warm days, and trout are more than happy to take them.
What they imitate
Terrestrials cover the land bugs that fall in: hoppers (big, buoyant, usually foam), ants (small, sometimes barely visible, deadly), and beetles (round, dark, a great searching fly). They ride in or on the surface film and often land with a plop that gets a trout’s attention.
How to fish it
Fish terrestrials tight to the banks and undercuts, where the naturals fall in, on a drag-free drift, sometimes with a deliberate plop to draw a look. A hopper also makes a great indicator fly with a small nymph dropped beneath it, the hopper-dropper, a summer standby.
Tip Fish them on warm, breezy afternoons and hug the banks. Wind blows terrestrials off the grass and onto the water, and trout hold tight to the bank waiting for them, so put your hopper or beetle right against the edge and be ready.